1. Field of the Invention
The present invention relates to a center pillar assembly of a 3-door vehicle. More particularly, the present invention relates to a center pillar assembly of a 3-door vehicle, in which it may not only reduce its manufacturing cost, but also it may increase its strength.
2. Description of Related Art
In general, an outer reinforcement member for a center pillar is the most important reinforcement member for protecting the deformation of the vehicle when the broad-collision of the vehicle occurs. However, in case of a 3-door vehicle, it equips a quarter glass instead of a rear door, which is different from a 5-door vehicle. Accordingly, an upper portion of the outer reinforcement member for the center pillar is formed in a cross section of ‘’-shape to be welded to a quarter glass flange of a side outer panel, in which it is not formed in a cross section of ‘’-shape.
Now, the center pillar assembly of the 3-door vehicle will be explained in more detail with reference to FIGS. 1 and 2.
As shown in FIGS. 1 and 2, the center pillar assembly of the 3-door vehicle is composed of a side outer panel 110, an outer reinforcement member 120 for the center pillar and a side inner panel 140, wherein a quarter glass flange 115 is formed in the side outer panel 110. Here, the outer reinforcement member 120 for the center pillar includes an upper portion A′ and a lower portion B′, and is welded to the inner part of the side outer panel 110. Also, the side inner panel 140 is welded to the inner part of the outer reinforcement member 120 for the center pillar so as to face each other.
The outer reinforcement member 120 for the center pillar plays a role in reinforcing the side of the vehicle, wherein it includes the upper portion A′ which is welded to the quarter glass flange 115, and the lower portion B′ which is extended along the bottom of the upper portion A′.
At this point, the lower portion B′ of the outer reinforcement member 120 for the center pillar is formed in the section of ‘’-shape to be profited from the broad-collision of the vehicle, but the upper portion A′ is formed in the section of ‘’-shape to be easily deformed by the broad-collision of the vehicle. Accordingly, because the strength of a ‘Neck’ part N is weak in which the ‘Neck’ part N is a part that two sections of the upper portion A′ and the lower portion B′ of the outer reinforcement member 120 for the center pillar are faced with each other, an additional reinforcement member 130 for reinforcing the ‘Neck’ part N is welded to the outer reinforcement member 120 for the center pillar.
On the other hand, recently, although an ultra-high strength steel over 980 MPa is generally used as a material of the outer reinforcement member 120 for the center pillar in order to accomplish for the light weight of the material, its section must be hardly changed when it uses the ultra-high strength steel. But, in case of the outer reinforcement member 120 for the center pillar according to the prior art, the sections of its upper portion A′ and its lower portion B′ must be steeply changed from the ‘’-shape to the ‘’-shape, and accordingly, it was difficult to press-mold the ultra-high strength steel.
Accordingly, as the material of the outer reinforcement member 120 for the center pillar, it used a moldable 440 MPa-class material. Also, the outer reinforcement member 120 for the center pillar was used to be molded using a hot stamping method with little restriction for formability although the ultra-high strength steel was used.
As described above, according to the center pillar assembly of the conventional 3-door vehicle, the section of the upper portion A′ of the outer reinforcement member 120 for the center pillar was formed in the ‘’-shape which is weak in the collision performance, and accordingly, there was a problem that the manufacturing cost is increased since the additional reinforcement member 130 for reinforcing the outer reinforcement member 120 for the center pillar must be used.
Besides, in case where the ultra-high strength steel is molded as a material of the outer reinforcement member 120 for the center pillar, it must use the hot stamping method with little restriction for formability, and accordingly, there was a problem that the manufacturing cost is increased. Also, in case where it is molded as the moldable 440 MPa-class material, there was a problem that its strength becomes weaken.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.